Magnetic Resonance Imaging (hereinafter “MRI”) is a fascinating technique, which allows for a non-invasive assessment of the anatomy and function of the heart, without exposure to ionizing radiation. MRI offers not only high spatial resolution, but also an excellent soft-tissue contrast. MRI is recognized as the leading modality for diagnostic imaging of numerous common diseases. The outstanding properties of the MRI technique are, however, countered by a number of limitations, including but not limited to the time-consuming data acquisition, which results in lengthy examinations compared to other imaging techniques.
Tagging the object to be scanned in MRI is a useful method for the assessment and quantification of the deformations of that object. For example, a human heart (myocardium) can be tagged before cardiac magnetic resonance imaging. Myocardial tagging technique has shown to be a useful magnetic resonance modality for the assessment and quantification of local myocardial function in a healthy and in a diseased state of the heart. The act of tagging produces a variable brightness pattern in subsequent images and the deformation of that pattern over time clearly indicates tissue motion.
Tagging through the use of tag-lines is an important tool in the determination of strain in an object of interest, which lacks prominent features, for example, a human heart. The structure and motion of an object, such as the heart (left ventricle), especially in the often clinically used short axis view, adapts best to the polar coordinate system. It is, therefore, advantageous if the tagging patterns also fit the polar coordinates to facilitate the analysis and also provide a more intuitive description of the myocardial deformation.
Since one of the most concerning issues in the strain imaging is the scan time, especially in the evaluation of the cardiac function under stress test, there is a need in the art for a faster method for reconstruction of polar MRI data.